1. Technical Field
The present invention relates to a specimen holder of a transmission electron microscope (TEM) capable of observing a specimen from 3 or more directions, and more particularly to, a specimen holder capable of 3-axis movement for TEM 3D analysis that is able to more accurately analyze the specimen by moving the observation point of the specimen to the center of the rotational axis, and by making the specimen rotated and tilted.
2. Description of the Related Art
To analyze the internal structure of a material by using TEM, a circular specimen having a diameter of about 3 mm through which an electron beampasses is prepared. The prepared specimen is mounted in a holder suitable for the analytical purpose, and the holder is inserted into the TEM.
Holders used in the TEM are classified as tilt holders, rotation holders, heating holders, cooling holders, and cryo-transfer holders according to the characteristics of holders. A specimen must be observed in various directions in order to analyze the internal structure of a material by using the TEM holder.
Holders having free tilting are used to analyze the specimen in various directions. These holders can be tilted by ±30° at maximum, and particularly up to by ±70° according to the gap of pole pieces of the TEM.
A specimen cradle is tilted for the tilting holder of ±30°. In case of tilting more than ±30°, a specimen is not easily observed due to the thickness of the specimen cradle itself. The tilting holder of ±70° has to use the holder tilting, which is possible for the TEM having a large pole-piece gap and a goniometer capable of high-angle tilting.
A double tilt holder manufactured to observe the specimen in various directions has advantage to use both the specimen cradle tilting (±30°) and the holder tilting (±70°), but has disadvantage difficult to analyze other orientations than these two tilting axes.
To solve this disadvantage, a rotation holder is manufactured. The rotation holder can rotate and observe all directions of the specimen when the observation point of the specimen is on the right center of the rotation axis. However, if the observation point is not located at the center of the rotation axis, it is easily moved beyond the field of view when the specimen cradle is rotated or the holder is tilted. At high magnification of TEM it is not easy to move the observation point into the field of view. Although the observation point is moved within the field of view, it is very difficult to perform 3D analysis by combining the images observed in various orientations, since a status in which the specimen is disposed is easily changed by the movement.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.